Dry cleaning machine

ABSTRACT

A dry cleaning machine comprises a main washing tank, a pair of solvent tanks for storing solvent connected to the washing tank and a continuous-action still and a condenser connected in series between the pair of solvent tanks. Electromechanical devices control the flow of air into and out of the main washing tank and control the circulation of solvent through the machine as a function of specific machine operating parameters to effectively prevent the loss of any solvent to the atmosphere.

United States Patent [191 Zucchini v [4 1 Apr. 2, 1974 DRY CLEANING MACHINE [75] Inventor: Guido Zucchini, Castelmaggiore,

ltaly [73] Assignee: Artigiani Meccanici Associati Societa di Fatto Castelmaggiore, Bologna, Italy [22] Filed: June 30, 1972 I21] App]. No.: 268,138

[30] Foreign Application Priority Data July 2, 1971 Italy 3464/70 52 us. c1. 621/12 R, 68/18 c [5 1] Int. Cl. D06f 33/02, D06f 43/08 [58] Field of Search. 68/18 R, 18 C, 18 F, '12 R [56] References Cited I UNITED STATES PATENTS Spalding 68/18 C X 2,019,896 11/1935 Edlich 68/18 C X 3,002,287 10/1961 Smith (18/18 C X Primary ExaminerWi11iam 1. Price Attorney, Agent, or FirmRobert E. Burns; EmmanuclJ. Lobato 15 71 ABSTRACT A dry cleaning machine comprises a main washing tank, a pair of solvent tanks for storing solvent connected to the washing tank and a continuous-action V still and a condenser connected in series between the 3 Claims, 3 Drawing Figures DRY CLEANING MACHINE DESCRIPTION OF THE INVENTION This invention relates to dry cleaning machines and, in particular, to continuous distillation dry. cleaning machines suitable for use with washing solvents having relatively low boiling points.

Known dry cleaning machines are provided, among other things, with one or'more vents through which the gases formed inside the washing tank during the operational cycles of the machine are continuously dis-. charged into the external atmosphere.

In order that this can be achieved, the makers of these particular machines are obliged to adopt special technical methods, of conventional types, which not only present installation problems but also have a high operating cost and, in the majority of instances, are the cause of losing a considerable amount of the solvent used in the washing cycle. This latter problem is most severe in machines and/or dry cleaning plants which use solvents with a low boiling point, such as, for example, Valclene, for which it is especially difficult to Y satisfactorily dissipate the gases which form inside the machines and/or dry cleaning plants in question during the operational cycle of the said machines and/or dry cleaning plants.

Continuous distillation dry cleaning machines are also known wherein there are at least two wash cycles and the solvent discharged from .the washing tank is subjected to a process of purification by evaporation, with the intent of separating the solvent from the impurities accumulated during the washing operation.

With such machines, there is, for each wash cycle, a

continuous distillation of the cycle solvent and thus a considerable amount of energy is required both for the supply of the still and for the supply of the condenser. or of the condensers, suitably arranged for the distilled solvent to be taken back to the liquid state from the gaseous state. An important object of this invention is to obviate the aforementioned difficulties and, in particular, to supply a dry cleaning machine on which the discharge of the gases from inside the washing tank during the operational cycle takes place under conditions which are such that it is possible to completely prevent the loss of solvent from occurring.

A further object of the invention is to supply a dry cleaning machine for which the running cost is minimum.

The above and other objects have been attained with the dry cleaning machine forming the subject of this in- .vention which comprises electro-mechanical follow-up means for allowing air to be sucked in from the outside or the air remaining inside the washing tank to be discharged into the external atmosphere as a function of the vacuum or pressure conditions within the machine, upon completion of the full operational cycle of the machine; a first and a second tank for the solvent, the first of which connecting with the tank discharge duct, the tanks being interconnected with an interposed continuous action still and a condenser for the distilled solvent being connected in series with the still; electromechanical follow-up means operative to allow the solvent coming from the washing tank, used for the last wash in the subsequent cycle without the said solvent passing through the aforementioned still and operative to allow the use of the solvent contained in the second solvent tank during the wash subsequent to the first, while contemporaneously, the solvent used for the first wash, discharged from the washing tank into the first solvent tank, is being distilled and sent to the aforementioned second solvent tank.

Further characteristics and advantages will emerge more clearly from the following description of a preferred but not the sole embodiment for the machine of the present invention, as illustrated purely for exemplification purposes in the accompanying drawings wherein:

FIG. 1 shows diagrammatically the aeration circuit for the machine forming the subject of the invention, referred to the circuit for the drying of the washed garments.

FIG. 2 is an electrical wiring diagramshowing how the various devices indicated in FIG. 1 are connected to the circuit.

FIG. 3 is a working diagram 'of the solvent washing circuit for the machine forming the subject of the invention.

It will be seen from FIG. 1 that the washing tank -1 communicates with an air filter 3 through a'duct 2.

A fan 5 has its intake connected to the air filter 3 through the duct 4 and its output connected to a condenser 7 through the duct 6.

The condenser 7 communicates, in turn, with a preheater 9 through a duct 8. The pre-heater 9 is connected, in turn, with the'washing tank 1 via a duct 10.

Two valves, installed to close the duct 2 and the duct 10 are indicated at 11 and 12, respectively,

A duct 13 communicates with the washing tank 1 and with the external atmosphere. A valve indicated at 14 is installed to close the duct 13.

A door 15 seals the washing tankl and its operation is dependent upon an interlocking device 16, of a known type, more about which will be. said in due course.

With reference to FIG. 2, a changeover switch is indicated at 17 and this is provided with a moving contact 17a and two fixed contacts 17b and 17c. The fixed contact 17b is connected to a relay 18 whose moving contact can operate on a fixed contact 18b and on a fixed contact 180, the former being connected to the device 16 for locking the door 15 and the latter to the control units belonging to the valve 11.

The fixed contact 17c is connected to a relay 19 whose moving contact 19a can operate on a fixed contact 19b and on a fixed contact 190, the former being connected to the control units belonging to the valve 12 and the latter to the control units belonging to the valve 14. Furthermore, the fixed contact'17c is also connected to a time relay 20 whose moving contact 20a can operate on a fixed contact 20b connected to the relay l8.

In relation to the foregoing, a description will now be given of the operation of the aeration circuit on the ma- Chine forming the subject of the invention, referred to the final stage in the operational cycle of the said machine.

When putting the machine into operation, the operator sets the changeover switch 17 on the fixed contact 17b and thus whattranspires is that the device 16 is energized, thereby locking the door 16 in its closed position, the valves 11 and 12 remain open and the valve l4 closed since only its control units are energized. lt ensues that during the full operational cycle of the machine, the cycle air in the circuit shown in FIG. 1 and any gases formed during the washing stage on account of the gasification of the solvent used, remain closed inside the said circuit without any possibility of their being purged into the external atmosphere (closed circuit).

In the final stage of the operational cycle of the machine, or in other words, during the stage when the washed garments are being dried, the fan 5 causes the cycle fluid in the said circuit to undergo forced circulation and thus the fluid passes through the filter 3 and the condenser 7 and is gradually purified until it is totally separated from the previously absorbed gases which, in accordance with known practices, are recovered through the condenser 7. As a result of the aforementioned gasification of the solvent, it is possible that a certain pressure is created inside the tank 1 which has to be balanced and destroyed before the tank sealing door is opened.

So that this can be done, the changeover switch 17 is set on the fixed contact 17c and this brings about the energization of the time relay 20 and of the relay 19. What actually happens is that the moving contact 19a operates on the fixed contact 19b, whilst the time relay 20 enables the relay 18 to be kept energized and this continues its action on the device 16 for locking the door 15.

In this first stage, the non-energized control units belonging to the valve 14 open the relief valve 14 and thus place the tank 1 in communication with the external atmosphere, whilst at the same time, the valve 12 is closed and this closes the duct 2.

After a certain pre-set amount of time has elapsed, the moving contact 20a of the time relay 20 ceases its action on the fixed contact 20b.

This results in the action of the relay 18 ceasing contemporaneously and its moving contact 18a ceases to operate on the fixed contact 18b and returns to the fixed contact 18c.

In consequence of the foregoing, the valve 11 is closed and this closes the duct 10. At the same time, the device 16 for locking the door 15 ceases to exercise an interlocking action and thus it is possible to open the said door.

It can be seen from the above that with the aforementioned method of construction, it is only possible to place the washing tank in communication with the external atmosphere once the complete washing operational cycle has ended, to enable the intake of air should the machine be in a state of vacuum or the discharge of impurity free air if there is a slight pressure in the machine, besides the fact that by closing the ducts 2 and which communicate with the washing tank, it is possible to isolate the tank itself from the rest of the circuit, thereby preventing any possible eventual leakage of gas into the atmosphere in which the machine is installed, at the time when the tank sealing door is opened.

In addition to this, the opening of the said door only becomes possible once the washing tank has already been placed in communication with the external atmosphere, that is to say, once any pressure which has been created inside the said tank has been destroyed.

On HO. 3 there are two tanks indicated at 21 and 22 and these contain the solvent used for washing the garments. Of the two, only the tank 21 connects, via a duct 23 with the-drain pipe in the tank 1, whilst the tank 22, which is placed at a different elevation with respect to the tank 21, is connected to the tank 1, througha duct 24.

A pump indicated at 25 drawing solvent out of the tank 21v and is connected, via a duct 26 to a still 27 and, via a branch pipe 28 to the tank 1.

The still 27 is connected direct to a condenser 34 which, through a duct 29 is linked with the tank 22.

Four valves, 30, 31, 32 and 33, respectively, serve to close the duct 23, the duct 26, the branch pipe 28 and the duct 24.

In relation to the foregoing, a description will now be given of the operation of the machine forming the subject of the invention, referred to the washing cycle in which, as previously stated, there are at least two washes. i

The solvent contained in the tank 21 is, in the first stage, sucked up by the pump 25 and, via the ducts 26 and 28 and the valve 32, is made to flow inside the tank 1. After the first wash has been completed, the valve 30 opens and the solvent contained in the tank 1 returns back into the tank 21 whence, again drawnup by the pump 25, it is made to flow into the still 27 through the duct 26 and the valve 31.

At thisjuncture, with valves 30, 31 and 32 closed, the

valve 33 opens and the solvent contained in the tank 22 flows inside the washing tank 1 for the garments to be given a second wash.

Contemporaneously, the distillation solvent passes through the condenser 34 and the duct 29 and into the tank 22, whilst the valve 33', in the meantime closed, prevents it from running out of the said tank.

The solvent contained in the tank 21 previously used for the final wash in the first washing cycle, is now used again for the subsequent washing cycle. Thus the pump 25 draws solvent out of the tank 21 and this solvent goes, through the ducts 26 and 28 and the valve 32 back into the washing tank 1 whence it is again discharged into the tank 21, is picked up again by the pump 25 and is passed into the still 27, after which'the second washing cycle is initiated in accordance with the aforementioned procedure.

It can be seen from the foregoing that according to the system adopted for the previously described washing cycle, it is possible to only continuously distil a part of the solvent used in the complete washing cycle and that in addition to this making it possible for a lesser quantity of solvent to be distilled in the unit of time, with a consequent noticeable saving on energy both for distillation and for condensation, it enables a fully distilled and free fromimpurity solvent to be available for the final wash, thereby favouring better conditions and improved washing results.

What we claim is:

l. A machine for dry cleaning comprising: a main washing tank, a closed forced aeration circuit for drying the cleaned garments or fabrics contained in said washing tank, electro-mechanical follow-up means operative as a function of the vacuum or pressure conditions within the machine to vent said tank to atmosphere, to allow air to be sucked in from the outside or the air remaining inside said main washing tank to be discharged to the external atmosphere upon completion of the full operational cycle of the machine; a closed circuit for washing and dry cleaning said fabrics in a wash cycle comprising two washes in each cycle, including a first and a second tank for the solvent; a tank discharge duct connecting said main washing tank to said first tankand a duct connecting said second tank to said main washing tank; duct means interconnecting said first and second tanks in series with a continuous action still and a condenser for the distilled solvent and additional duct means connecting said first tank directly to said main washing tank; and other electro-mechanical follow-up means operative to allow the solvent discharged from the washing tank and used for the last wash in the first cycle, to bypass said still and to be returned to the washing tank through said last mentioned duct means and to be'utilized' for the first wash in the subsequent cycle without said solvent passing through the aforementioned still and operative to allow the use of the solvent contained in the second solvent tank during the wash subsequent to the first while contemporaneously, the solvent used for the first wash, discharged from the washing tank into the first solvent tank, is being distilled and sent to the aforementioned second solvent tank;

2. A machine according to claim 1 wherein said main washing tank is provided with a sealing door and an interlocking device is connected to said electromechanical follow-up means operative as a function of the vacuum or pressure conditions within the machine to allow air to be sucked in from the outside or the air remaining inside said main washing tank to be discharged to the external atmosphere upon completion of the full operational cycle of the machine; said interlocking device being connected to the washing tank sealing door and permitting the said door to be opened for removal of the cleaned fabrics only after the intake or the discharge of air from and into the external atmosphere has first taken place.

3. A machine according to claim 2, including in said aeration circuit for drying the washed garments at least two valves connected in the ducts of said aeration circuit and controlled by said followup means which enable the gases to be discharged into the external atmosphere and being operative to close the ducts at the time the washing tank sealing door is opened to prevent 

1. A machine for dry cleaning comprising: a main washing tank, a closed forced aeration circuit for drying the cleaned garments or fabrics contained in said washing tank, electro-mechanical follow-up means operative as a function of the vacuum or pressure conditions within the machine to vent said tank to atmosphere, to allow air to be sucked in from the outside or the air remaining inside said main washing tank to be discharged to the external atmosphere upon completion of the full operational cycle of the machine; a closed circuit for washing and dry cleaning said fabrics in a wash cycle comprising two washes in each cycle, including a first and a second tank for the solvent; a tank discharge duct connecting said main washing tank to said first tank and a duct connecting said second tank to said main washing tank; duct means interconnecting said first and second tanks in series with a continuous action still and a condenser for the distilled solvent and additional duct means connecting said first tank directly to said main washing tank; and other electromechanical follow-up means operative to allow the solvent discharged from the washing tank and used for the last wash in the first cycle, to bypass said still and to be returned to the washing tank through said last mentioned duct means and to be utilized for the first wash in the subsequent cycle without said solvent passing through the aforementioned still and operative to allow the use of the solvent contained in the second solvent tank during the wash subsequent to the first while contemporaneously, the solvent used for the first wash, discharged from the washing tank into the first solvent tank, is being distilled and sent to the aforementioned second solvent tank.
 2. A machine according to claim 1 wherein said main washing tank is provided with a sealing door and an interlocking device is connected to said electromechanical follow-up means operative as a function of the vacuum or pressure conditions within the machine to allow air to be sucked in from the outside or the air remaining inside said main washing tank to be discharged to the external atmosphere upon completion of the full operational cycle of the machine; said interlocking device bEing connected to the washing tank sealing door and permitting the said door to be opened for removal of the cleaned fabrics only after the intake or the discharge of air from and into the external atmosphere has first taken place.
 3. A machine according to claim 2, including in said aeration circuit for drying the washed garments at least two valves connected in the ducts of said aeration circuit and controlled by said followup means which enable the gases to be discharged into the external atmosphere and being operative to close the ducts at the time the washing tank sealing door is opened to prevent opening of the remainder of the circuit to atmosphere. 